Characterisation of InAs-based epilayers by FTIR spectroscopy
- Authors: Baisitse, Tshepiso Revonia
- Date: 2007
- Subjects: Fourier transform infrared spectroscopy , Gallium arsenide semiconductors
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10534 , http://hdl.handle.net/10948/474 , Fourier transform infrared spectroscopy , Gallium arsenide semiconductors
- Description: This study focuses on the characterization of InAs and InAs1-xSbx epitaxial layers by infrared reflectance and transmittance spectroscopy and Hall measurements. Reflectance measurements were performed in order to obtain the dielectric parameters and to extract from these information about the electrical properties (mobility and carrier concentration) of this important III-V material system. The transmittance measurements were used to determine the bandgap of InAsSb. Infrared reflectivity and transmittance measurements were performed in the wavelength range 200 – 2000 cm-1 on InAs and InAsSb layers grown on three types of substrates. A classical two oscillator model that takes into account both the free carriers and the lattice, was used to analyse the reflectance data using the BMDP® computer curve fitting software. The dielectric parameters and the electrical properties (carrier concentration and mobility) were extracted from the simulations. Due to the low free carrier concentration in the epitaxial structures, the plasma resonance frequency (ωp) values obtained from the simulations of reflectance spectra measured above 200 cm-1, were in the order of 20-30 cm-1. These low values were confirmed by direct measurements of ωp in reflectance spectra obtained in the range 15-200 cm-1. The simulated carrier concentration and mobility values determined optically were compared to the values determined by Hall measurements at room temperature and previously reported values by other researchers. The simulated values obtained were in reasonable agreement with the Hall values. The simulated and measured carrier concentrations obtained for InAs layers were significantly higher than the intrinsic carrier concentration for InAs at room temperature, indicating notable concentrations of donors resulting from the growth process.
- Full Text:
- Date Issued: 2007
- Authors: Baisitse, Tshepiso Revonia
- Date: 2007
- Subjects: Fourier transform infrared spectroscopy , Gallium arsenide semiconductors
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10534 , http://hdl.handle.net/10948/474 , Fourier transform infrared spectroscopy , Gallium arsenide semiconductors
- Description: This study focuses on the characterization of InAs and InAs1-xSbx epitaxial layers by infrared reflectance and transmittance spectroscopy and Hall measurements. Reflectance measurements were performed in order to obtain the dielectric parameters and to extract from these information about the electrical properties (mobility and carrier concentration) of this important III-V material system. The transmittance measurements were used to determine the bandgap of InAsSb. Infrared reflectivity and transmittance measurements were performed in the wavelength range 200 – 2000 cm-1 on InAs and InAsSb layers grown on three types of substrates. A classical two oscillator model that takes into account both the free carriers and the lattice, was used to analyse the reflectance data using the BMDP® computer curve fitting software. The dielectric parameters and the electrical properties (carrier concentration and mobility) were extracted from the simulations. Due to the low free carrier concentration in the epitaxial structures, the plasma resonance frequency (ωp) values obtained from the simulations of reflectance spectra measured above 200 cm-1, were in the order of 20-30 cm-1. These low values were confirmed by direct measurements of ωp in reflectance spectra obtained in the range 15-200 cm-1. The simulated carrier concentration and mobility values determined optically were compared to the values determined by Hall measurements at room temperature and previously reported values by other researchers. The simulated values obtained were in reasonable agreement with the Hall values. The simulated and measured carrier concentrations obtained for InAs layers were significantly higher than the intrinsic carrier concentration for InAs at room temperature, indicating notable concentrations of donors resulting from the growth process.
- Full Text:
- Date Issued: 2007
Characterization of WC-VC-Co and WC-VC-TiC-Co hardmetals
- Authors: Hashe, Nobom Gretta
- Date: 2007
- Subjects: Carbides , Hard materials
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10533 , http://hdl.handle.net/10948/522 , http://hdl.handle.net/10948/d1011723 , Carbides , Hard materials
- Description: This thesis contains the results of a study focused on cubic carbide and carbonitride grain growth retardation in hardmetals. Large additions of VC, or VC and TiC, or (W,V)C were made to the WC-Co hardmetal, which was then sintered in vacuum or nitrogen. The effectiveness of Ti as the grain growth inhibitor, and the influence of nitrogen sintering on grain coarsening were investigated using transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffractrometry (XRD) and atom probe field ion microscope (APFIM). Analysis of vacuum-sintered WC-VC-Co revealed that the cubic carbide grains have a core-rim structure. Ti was found to be a core-rim inhibitor in vacuum-sintered WCVC- TiC-Co. The average cubic carbide grain size distribution for the vacuumsintered materials was narrowed in the Ti-containing hardmetal. The nitrogen-sintered WC-VC-TiC-Co consisted of two phases of cubic carbonitride, one with high Ti-content and the other with high (W,V)-content. The surface region of the nitrogen-sintered WC-VC-TiC-Co was covered with a cubic carbonitride phase. Similar phenomena was observed in nitrogen-sintered WC-VC-Co where two types of carbonitrides were found, those with high V-content and the others with low Vcontent. A gradient zone, consisting of fine WC grains in a Co-rich binder and free from cubic carbonitride grains, was created in the surface region. The nitrogensintered materials consisted of a narrow grain size distribution. The use of (W,V)C as a starting powder affected the mechanical properties of the material with the WC-(W,V)C-Co material being the hardest of those produced in this study. Addition of (W,V)C powder to WC-Co was shown to be the most effective way to limit the cubic carbide grain size during sintering and produce a hard material. The cubic carbide grain size in the material produced this way was the smallest of all studied.
- Full Text:
- Date Issued: 2007
- Authors: Hashe, Nobom Gretta
- Date: 2007
- Subjects: Carbides , Hard materials
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10533 , http://hdl.handle.net/10948/522 , http://hdl.handle.net/10948/d1011723 , Carbides , Hard materials
- Description: This thesis contains the results of a study focused on cubic carbide and carbonitride grain growth retardation in hardmetals. Large additions of VC, or VC and TiC, or (W,V)C were made to the WC-Co hardmetal, which was then sintered in vacuum or nitrogen. The effectiveness of Ti as the grain growth inhibitor, and the influence of nitrogen sintering on grain coarsening were investigated using transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffractrometry (XRD) and atom probe field ion microscope (APFIM). Analysis of vacuum-sintered WC-VC-Co revealed that the cubic carbide grains have a core-rim structure. Ti was found to be a core-rim inhibitor in vacuum-sintered WCVC- TiC-Co. The average cubic carbide grain size distribution for the vacuumsintered materials was narrowed in the Ti-containing hardmetal. The nitrogen-sintered WC-VC-TiC-Co consisted of two phases of cubic carbonitride, one with high Ti-content and the other with high (W,V)-content. The surface region of the nitrogen-sintered WC-VC-TiC-Co was covered with a cubic carbonitride phase. Similar phenomena was observed in nitrogen-sintered WC-VC-Co where two types of carbonitrides were found, those with high V-content and the others with low Vcontent. A gradient zone, consisting of fine WC grains in a Co-rich binder and free from cubic carbonitride grains, was created in the surface region. The nitrogensintered materials consisted of a narrow grain size distribution. The use of (W,V)C as a starting powder affected the mechanical properties of the material with the WC-(W,V)C-Co material being the hardest of those produced in this study. Addition of (W,V)C powder to WC-Co was shown to be the most effective way to limit the cubic carbide grain size during sintering and produce a hard material. The cubic carbide grain size in the material produced this way was the smallest of all studied.
- Full Text:
- Date Issued: 2007
Child sex tourism in South African law
- Authors: Chetty, Kasturi
- Date: 2007
- Subjects: Child sexual abuse -- South Africa , Sex tourism -- Law and legislation -- South Africa , Sex crimes -- South Africa , Child prostitution -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10276 , http://hdl.handle.net/10948/485 , Child sexual abuse -- South Africa , Sex tourism -- Law and legislation -- South Africa , Sex crimes -- South Africa , Child prostitution -- South Africa
- Description: Child sex tourism is tourism organised with the primary purpose of facilitating a commercial sexual relationship with a child. It involves a segment of the local child sex industry that is directly connected to both an international and domestic tourist market. The increase of tourism has brought with it complications in that tourism is being used as a means for sex tourists to initiate contact with children. Aside from child sex tourists who are paedophiles, there are those who engage in the opportunistic exploitation of children while travelling on business or for other reasons. There are a number of social and economic factors leading to child sex tourism and the effect is that child victims are exposed to immediate harm, irreversible damage and even death. As South Africa's tourism industry expands into one of the country’s top earners of foreign currency, it is unfortunate to note that its child sex tourist trade is also on the increase. Reports show that sex tours are as easily organised as wine route tours in Cape Town. Commercial sexual exploitation of children is prevalent in South Africa and has become more organised in recent years. A comprehensive response to the problem is essential to ensure that South Africa does not become a “safe haven” for child sex tourists. Effective laws at home and the extraterritorial application of these laws to prosecute South African nationals for crimes committed abroad are imperative. Significant steps are being taken both nationally and internationally to target child sex tourism. South Africa has ratified several international instruments on children’s rights, trafficking in persons, child labour, and discrimination against women and young girls, all of which relate to child sex tourism. In doing so, South Africa has made an international commitment to uphold the provisions of these instruments and give effect to them. South Africa is therefore under an international obligation to create the necessary structures and apply mechanisms and resources to combat child sex tourism.
- Full Text:
- Date Issued: 2007
- Authors: Chetty, Kasturi
- Date: 2007
- Subjects: Child sexual abuse -- South Africa , Sex tourism -- Law and legislation -- South Africa , Sex crimes -- South Africa , Child prostitution -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10276 , http://hdl.handle.net/10948/485 , Child sexual abuse -- South Africa , Sex tourism -- Law and legislation -- South Africa , Sex crimes -- South Africa , Child prostitution -- South Africa
- Description: Child sex tourism is tourism organised with the primary purpose of facilitating a commercial sexual relationship with a child. It involves a segment of the local child sex industry that is directly connected to both an international and domestic tourist market. The increase of tourism has brought with it complications in that tourism is being used as a means for sex tourists to initiate contact with children. Aside from child sex tourists who are paedophiles, there are those who engage in the opportunistic exploitation of children while travelling on business or for other reasons. There are a number of social and economic factors leading to child sex tourism and the effect is that child victims are exposed to immediate harm, irreversible damage and even death. As South Africa's tourism industry expands into one of the country’s top earners of foreign currency, it is unfortunate to note that its child sex tourist trade is also on the increase. Reports show that sex tours are as easily organised as wine route tours in Cape Town. Commercial sexual exploitation of children is prevalent in South Africa and has become more organised in recent years. A comprehensive response to the problem is essential to ensure that South Africa does not become a “safe haven” for child sex tourists. Effective laws at home and the extraterritorial application of these laws to prosecute South African nationals for crimes committed abroad are imperative. Significant steps are being taken both nationally and internationally to target child sex tourism. South Africa has ratified several international instruments on children’s rights, trafficking in persons, child labour, and discrimination against women and young girls, all of which relate to child sex tourism. In doing so, South Africa has made an international commitment to uphold the provisions of these instruments and give effect to them. South Africa is therefore under an international obligation to create the necessary structures and apply mechanisms and resources to combat child sex tourism.
- Full Text:
- Date Issued: 2007
Clients' views on construction and design team competencies
- Authors: Crafford, Gerrit Jacobus
- Date: 2007
- Subjects: Construction industry -- Employees , Core competencies
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9679 , http://hdl.handle.net/10948/490 , Construction industry -- Employees , Core competencies
- Description: The effectiveness of the design and construction team in meeting clients’ requirements entirely depends on the competency proficiency of the design and construction teams. This research presents a model of the important competencies required by the design and construction teams in order to provide a competent service as seen by the client. A review of related literature followed by interviews by selected practitioners yielded 29 architectural competencies, 31 civil engineering competencies, 32 construction management competencies, 31 project management competencies, and 33 quantity surveying competencies that were presented in a structured questionnaire. The questionnaire was completed by 52 developers from a census of developers and municipality managers in South Africa. Respondents were asked to rank or rate: the level of importance of each competency for a career in that specific discipline; how evident that competency is in the specific discipline in South Africa; the level of importance of the performance parameters to clients, and the extent to which the various disciplines realise client satisfaction relative to the various performance parameters. The techniques of re-scaling, principal component analysis, content analysis, ranking and quadrant analysis were applied to the data. Results showed a high degree of consistency among respondents in all disciplines, regardless of the demographic differences in the importance of the competencies. A factor solution was obtained for every discipline using principal component analysis on the important competencies of each discipline. The various factor solutions were in turn used to formulate a simplified model. The model shows that the factors are interdependent and interacting. The model indicates that primary competencies for each profession are supported by mostly secondary competencies. These factors v are in turn influenced by the inter-relationships between the practitioners, continued professional development/ research and universities, which are then in turn, influenced the governing bodies. The local and global environment then ultimately influences the governing bodies. An Importance-Evidence quadrant analysis was undertaken in order to integrate the rankings of the current importance levels and current proficiency levels for each discipline’s competencies, which helped to identify areas in which education and training is immediately needed. Respondents ranked all nine performance parameters above average which indicates that there are more than the traditional performance parameters of cost, quality, and time involved in satisfying clients. The research concluded that vital feedback from clients regarding the competencies required by the respective professionals in the design and construction team was obtained.
- Full Text:
- Date Issued: 2007
- Authors: Crafford, Gerrit Jacobus
- Date: 2007
- Subjects: Construction industry -- Employees , Core competencies
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9679 , http://hdl.handle.net/10948/490 , Construction industry -- Employees , Core competencies
- Description: The effectiveness of the design and construction team in meeting clients’ requirements entirely depends on the competency proficiency of the design and construction teams. This research presents a model of the important competencies required by the design and construction teams in order to provide a competent service as seen by the client. A review of related literature followed by interviews by selected practitioners yielded 29 architectural competencies, 31 civil engineering competencies, 32 construction management competencies, 31 project management competencies, and 33 quantity surveying competencies that were presented in a structured questionnaire. The questionnaire was completed by 52 developers from a census of developers and municipality managers in South Africa. Respondents were asked to rank or rate: the level of importance of each competency for a career in that specific discipline; how evident that competency is in the specific discipline in South Africa; the level of importance of the performance parameters to clients, and the extent to which the various disciplines realise client satisfaction relative to the various performance parameters. The techniques of re-scaling, principal component analysis, content analysis, ranking and quadrant analysis were applied to the data. Results showed a high degree of consistency among respondents in all disciplines, regardless of the demographic differences in the importance of the competencies. A factor solution was obtained for every discipline using principal component analysis on the important competencies of each discipline. The various factor solutions were in turn used to formulate a simplified model. The model shows that the factors are interdependent and interacting. The model indicates that primary competencies for each profession are supported by mostly secondary competencies. These factors v are in turn influenced by the inter-relationships between the practitioners, continued professional development/ research and universities, which are then in turn, influenced the governing bodies. The local and global environment then ultimately influences the governing bodies. An Importance-Evidence quadrant analysis was undertaken in order to integrate the rankings of the current importance levels and current proficiency levels for each discipline’s competencies, which helped to identify areas in which education and training is immediately needed. Respondents ranked all nine performance parameters above average which indicates that there are more than the traditional performance parameters of cost, quality, and time involved in satisfying clients. The research concluded that vital feedback from clients regarding the competencies required by the respective professionals in the design and construction team was obtained.
- Full Text:
- Date Issued: 2007
Co-engaged learning : Xhosa women's narratives on traditional foods
- Authors: Jolly, Rachel
- Date: 2007
- Subjects: Xhosa (African people) -- Social life and customs -- South Africa -- Grahamstown Women, Xhosa -- South Africa -- Grahamstown Nutrition -- Study and teaching -- South Africa -- Grahamstown Ethnoscience -- Study and teaching -- South Africa -- Grahamstown AIDS (Disease) -- South Africa -- Grahamstown HIV infections -- South Africa -- Grahamstown Environmental education -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1450 , http://hdl.handle.net/10962/d1003331
- Description: This interpretive case study examines Grahamstown East Xhosa women's narratives on the nutritional value of traditional foods. It reviews reflexive learning interactions apparent in the co-engaged narratives of food preparation practices. The research design incorporates methods of reflective co-engagement through which a small team of women were approached as 'co-researchers' in order to work together on shared, local knowledge capital and nutrition concerns. It draws on findings generated using a combination of semi-structured interviews, cooking demonstrations, videography, photographs and field observations as methods of data collection. Data were member-checked and reviewed in a rural context before the emerging evidence was analyzed using Bassey's (1999) analytical statements. Contextual factors influencing the study are high poverty, unemployment and HIV/AIDS prevalence where nutrition levels have been found to be low. The women making up the study have spent the majority of their lives in the peri-urban area of Grahamstown and in some cases, are more than one generation removed from rural living and its associated knowledge. The accompanying shift to modernization was found to influence the interplay between their narratives and practice. Indigenous Knowledge is often characterized by being situated in practice with the knowledge-holders often not 'knowing that they know.' This study concludes that it is not possible to assume that knowledge can always be consciously expressed, especially when that knowledge is embedded in practice. Related to this, co-engagement and diversity among the group gave rise to greater disequilibrium as well as making the knowledge more explicit and hence, available for reflection. The study suggests that through the process of co-engagement and deliberation around indigenous ways of knowing, agency and cultural identity appears to be enabled and strengthened.
- Full Text:
- Date Issued: 2007
- Authors: Jolly, Rachel
- Date: 2007
- Subjects: Xhosa (African people) -- Social life and customs -- South Africa -- Grahamstown Women, Xhosa -- South Africa -- Grahamstown Nutrition -- Study and teaching -- South Africa -- Grahamstown Ethnoscience -- Study and teaching -- South Africa -- Grahamstown AIDS (Disease) -- South Africa -- Grahamstown HIV infections -- South Africa -- Grahamstown Environmental education -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1450 , http://hdl.handle.net/10962/d1003331
- Description: This interpretive case study examines Grahamstown East Xhosa women's narratives on the nutritional value of traditional foods. It reviews reflexive learning interactions apparent in the co-engaged narratives of food preparation practices. The research design incorporates methods of reflective co-engagement through which a small team of women were approached as 'co-researchers' in order to work together on shared, local knowledge capital and nutrition concerns. It draws on findings generated using a combination of semi-structured interviews, cooking demonstrations, videography, photographs and field observations as methods of data collection. Data were member-checked and reviewed in a rural context before the emerging evidence was analyzed using Bassey's (1999) analytical statements. Contextual factors influencing the study are high poverty, unemployment and HIV/AIDS prevalence where nutrition levels have been found to be low. The women making up the study have spent the majority of their lives in the peri-urban area of Grahamstown and in some cases, are more than one generation removed from rural living and its associated knowledge. The accompanying shift to modernization was found to influence the interplay between their narratives and practice. Indigenous Knowledge is often characterized by being situated in practice with the knowledge-holders often not 'knowing that they know.' This study concludes that it is not possible to assume that knowledge can always be consciously expressed, especially when that knowledge is embedded in practice. Related to this, co-engagement and diversity among the group gave rise to greater disequilibrium as well as making the knowledge more explicit and hence, available for reflection. The study suggests that through the process of co-engagement and deliberation around indigenous ways of knowing, agency and cultural identity appears to be enabled and strengthened.
- Full Text:
- Date Issued: 2007
Collaborative research with traditional African health practitioners of the Nelson Mandela Metropole : antimicrobial, anticancer and anti-diabetic activities of five medicinal plants
- Authors: Van Huyssteen, Mea
- Date: 2007
- Subjects: Medicinal plants -- South Africa -- Port Elizabeth , Healers -- South Africa -- Port Elizabeth , Anti-infective agents
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10148 , http://hdl.handle.net/10948/663 , Medicinal plants -- South Africa -- Port Elizabeth , Healers -- South Africa -- Port Elizabeth , Anti-infective agents
- Description: The promotion and development of indigenous knowledge pertaining to the traditional African healing system is one of the prime objectives set out by the South African government. Despite excellent research opportunities and funding, the biggest problem with ethnopharmacological research is a lack of interaction with indigenous communities, which tends to dilute the benefits this research has to offer these communities. The primary aim of this study was thus to promote the traditional African healing system through collaborative medicinal plant research with local traditional health practitioners. The research collaboration aimed to validate some biological activities of traditional remedies used by collaborating traditional health practitioners and ensured interactive sessions where scientific literature, research practices, findings and relevant legislation were discussed and debated. The joint development of a medicinal garden was a valuable tool in realising these goals. Aqueous and ethanol extracts of Bulbine frutescens, Ornithogalum longibracteatum, Ruta graveolens, Tarchonanthus camphoratus and Tulbaghia violacea were selected for antimicrobial, anticancer and anti-diabetic screening, because of their sustainable utilisation potential. The ethanol extract of T. violacea produced the best antimicrobial activity on Bacillus subtilis (100% growth inhibition) and Candida albicans (89% growth inhibition) at 250 μg/ml. The EC50 for the ethanol extract of T. violacea against HT29 colon cancer cells was 101 μg/ml. The aqueous extracts of B. frutescens and T. camphoratus (0.5 and 50 μg/ml) produced the highest overall glucose uptake activity in Chang liver and C2C12 muscle cells. T. camphoratus was unanimously chosen by participating practitioners as the plant to be investigated further. The aqueous extract of T. camphoratus increased glucose uptake in C2C12 muscle cells through increased translocation of GLUT4 to the plasma membrane and activation of the PI3-kinase and AMP-kinase pathways. It produced some alpha-glucosidase inhibitory activity at concentrations of ≥ 200 μg/ml. Apart from interactive feedback seminars at which the findings were presented to participating practitioners, all scientific literature regarding the plants was summarised, translated, compiled and given to participating practitioners in written format. An indigenous knowledge agreement has been negotiated and will formalise the collaboration in future. It is recommended that future research focuses on plants with economic development potential that can be cultivated in the medicinal garden.
- Full Text:
- Date Issued: 2007
- Authors: Van Huyssteen, Mea
- Date: 2007
- Subjects: Medicinal plants -- South Africa -- Port Elizabeth , Healers -- South Africa -- Port Elizabeth , Anti-infective agents
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10148 , http://hdl.handle.net/10948/663 , Medicinal plants -- South Africa -- Port Elizabeth , Healers -- South Africa -- Port Elizabeth , Anti-infective agents
- Description: The promotion and development of indigenous knowledge pertaining to the traditional African healing system is one of the prime objectives set out by the South African government. Despite excellent research opportunities and funding, the biggest problem with ethnopharmacological research is a lack of interaction with indigenous communities, which tends to dilute the benefits this research has to offer these communities. The primary aim of this study was thus to promote the traditional African healing system through collaborative medicinal plant research with local traditional health practitioners. The research collaboration aimed to validate some biological activities of traditional remedies used by collaborating traditional health practitioners and ensured interactive sessions where scientific literature, research practices, findings and relevant legislation were discussed and debated. The joint development of a medicinal garden was a valuable tool in realising these goals. Aqueous and ethanol extracts of Bulbine frutescens, Ornithogalum longibracteatum, Ruta graveolens, Tarchonanthus camphoratus and Tulbaghia violacea were selected for antimicrobial, anticancer and anti-diabetic screening, because of their sustainable utilisation potential. The ethanol extract of T. violacea produced the best antimicrobial activity on Bacillus subtilis (100% growth inhibition) and Candida albicans (89% growth inhibition) at 250 μg/ml. The EC50 for the ethanol extract of T. violacea against HT29 colon cancer cells was 101 μg/ml. The aqueous extracts of B. frutescens and T. camphoratus (0.5 and 50 μg/ml) produced the highest overall glucose uptake activity in Chang liver and C2C12 muscle cells. T. camphoratus was unanimously chosen by participating practitioners as the plant to be investigated further. The aqueous extract of T. camphoratus increased glucose uptake in C2C12 muscle cells through increased translocation of GLUT4 to the plasma membrane and activation of the PI3-kinase and AMP-kinase pathways. It produced some alpha-glucosidase inhibitory activity at concentrations of ≥ 200 μg/ml. Apart from interactive feedback seminars at which the findings were presented to participating practitioners, all scientific literature regarding the plants was summarised, translated, compiled and given to participating practitioners in written format. An indigenous knowledge agreement has been negotiated and will formalise the collaboration in future. It is recommended that future research focuses on plants with economic development potential that can be cultivated in the medicinal garden.
- Full Text:
- Date Issued: 2007
Combined and additive effects of assembly tasks and constrained body postures
- Authors: Skelton, Sarah Anne
- Date: 2007
- Subjects: Musculoskeletal system -- Diseases , Human engineering , Posture , Posture disorders , Work -- Physiological aspects , Occupational diseases , Manual work , Job stress
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5107 , http://hdl.handle.net/10962/d1005185 , Musculoskeletal system -- Diseases , Human engineering , Posture , Posture disorders , Work -- Physiological aspects , Occupational diseases , Manual work , Job stress
- Description: Despite extensive research into musculoskeletal disorders (MSDs) they continue to plague workers. Manual materials handling (MMH), in particular the concurrence of load manipulation and awkward body posture, has been identified as a key factor in the onset of MSDs. Only a few studies have looked at the interaction between manipulation tasks and working posture during assembly tasks and as a result their relationship has not been widely explored. Assessing the stresses resulting from individual task factors and body posture in isolation and adding them together may be too simplified to estimate an overall risk profile, since this does not take into account that there may be a non-linear interaction in strain responses when manipulation task and body posture interact. Therefore, the present study investigated biophysical, physiological and psychophysical responses to combined tasks, rather than individual tasks of body posture and manipulative tasks. The objective of the research was to establish the interactive effects of constrained body postures and manipulative tasks and to identify whether a cumulative or compensatory reaction occurs during this interaction. Nine conditions were assessed in a laboratory setting, which included combinations of three working postures (standing, sitting and stooping) and three assembly tasks (torque wrenching, precision and no task). Thirty-six subjects were required to complete all nine conditions, with each condition lasting ninety seconds. Muscle activity was recorded for seven muscles from the upper extremity, trunk and lower extremity regions and was complemented by physiological (heart rate, tidal volume, minute ventilation, oxygen consumption, energy expenditure and breathing frequency) and psychophysical (body discomfort) data. At the completion of all nine conditions subjects completed a retrospective psychophysical rating questionnaire pertaining to discomfort felt during the conditions. Responses obtained for the different task and posture combinations revealed compensatory reactions (additive > combined) for most of the conditions assessed for the biomechanical and physiological responses. In the majority of cases for muscle activity, no significant differences were found between the combined and the additive effects (p < 0.05), while for the physiological responses there were mostly significant differences observed. Psychophysical responses indicated that there was a significant difference overall between the additive and combined effects. The results of this study demonstrate that in order to identify risk areas, manipulation tasks and constrained working postures may be considered either in isolation and added together (additive) or as a combined task, since there were very few significant differences observed between these two effects. Further studies are required, however, to provide conclusive evidence.
- Full Text:
- Date Issued: 2007
- Authors: Skelton, Sarah Anne
- Date: 2007
- Subjects: Musculoskeletal system -- Diseases , Human engineering , Posture , Posture disorders , Work -- Physiological aspects , Occupational diseases , Manual work , Job stress
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5107 , http://hdl.handle.net/10962/d1005185 , Musculoskeletal system -- Diseases , Human engineering , Posture , Posture disorders , Work -- Physiological aspects , Occupational diseases , Manual work , Job stress
- Description: Despite extensive research into musculoskeletal disorders (MSDs) they continue to plague workers. Manual materials handling (MMH), in particular the concurrence of load manipulation and awkward body posture, has been identified as a key factor in the onset of MSDs. Only a few studies have looked at the interaction between manipulation tasks and working posture during assembly tasks and as a result their relationship has not been widely explored. Assessing the stresses resulting from individual task factors and body posture in isolation and adding them together may be too simplified to estimate an overall risk profile, since this does not take into account that there may be a non-linear interaction in strain responses when manipulation task and body posture interact. Therefore, the present study investigated biophysical, physiological and psychophysical responses to combined tasks, rather than individual tasks of body posture and manipulative tasks. The objective of the research was to establish the interactive effects of constrained body postures and manipulative tasks and to identify whether a cumulative or compensatory reaction occurs during this interaction. Nine conditions were assessed in a laboratory setting, which included combinations of three working postures (standing, sitting and stooping) and three assembly tasks (torque wrenching, precision and no task). Thirty-six subjects were required to complete all nine conditions, with each condition lasting ninety seconds. Muscle activity was recorded for seven muscles from the upper extremity, trunk and lower extremity regions and was complemented by physiological (heart rate, tidal volume, minute ventilation, oxygen consumption, energy expenditure and breathing frequency) and psychophysical (body discomfort) data. At the completion of all nine conditions subjects completed a retrospective psychophysical rating questionnaire pertaining to discomfort felt during the conditions. Responses obtained for the different task and posture combinations revealed compensatory reactions (additive > combined) for most of the conditions assessed for the biomechanical and physiological responses. In the majority of cases for muscle activity, no significant differences were found between the combined and the additive effects (p < 0.05), while for the physiological responses there were mostly significant differences observed. Psychophysical responses indicated that there was a significant difference overall between the additive and combined effects. The results of this study demonstrate that in order to identify risk areas, manipulation tasks and constrained working postures may be considered either in isolation and added together (additive) or as a combined task, since there were very few significant differences observed between these two effects. Further studies are required, however, to provide conclusive evidence.
- Full Text:
- Date Issued: 2007
Competitive strategies and entry strategies of low cost airline incumbent 1time Airline
- Authors: Potgieter, Diane
- Date: 2007
- Subjects: 1time Airline (South Africa) 1time Airline (South Africa) -- Planning Airlines -- South Africa -- Management Airlines -- South Africa -- Marketing Airlines -- South Africa -- Cost of operation Competition -- South Africa Strategic planning
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:810 , http://hdl.handle.net/10962/d1007606
- Description: This dissertation reports on the factors that contributed to the successful entry strategy of 1time Airline, a low cost carrier, into the South African airline industry as well as its competitive strategies within this context. Research interviews were conducted in November 2005 and research material gathered until end January 2006. Key issues include an evaluation of 1time's business model in relation to other low cost entrants as well as against material sourced through interviews with 1time Airline management, employees and consumers of the airline's product. Porter's Generic Strategies and Five Forces model are used as a framework in evaluating the airline. It is found that Nohria, Joyce and Robertson's "4+2 Formula" is effectively implemented at the airline, but that further implementation of Game Theory in terms of alliances should be investigated for continued success and sustainability.
- Full Text:
- Date Issued: 2007
- Authors: Potgieter, Diane
- Date: 2007
- Subjects: 1time Airline (South Africa) 1time Airline (South Africa) -- Planning Airlines -- South Africa -- Management Airlines -- South Africa -- Marketing Airlines -- South Africa -- Cost of operation Competition -- South Africa Strategic planning
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:810 , http://hdl.handle.net/10962/d1007606
- Description: This dissertation reports on the factors that contributed to the successful entry strategy of 1time Airline, a low cost carrier, into the South African airline industry as well as its competitive strategies within this context. Research interviews were conducted in November 2005 and research material gathered until end January 2006. Key issues include an evaluation of 1time's business model in relation to other low cost entrants as well as against material sourced through interviews with 1time Airline management, employees and consumers of the airline's product. Porter's Generic Strategies and Five Forces model are used as a framework in evaluating the airline. It is found that Nohria, Joyce and Robertson's "4+2 Formula" is effectively implemented at the airline, but that further implementation of Game Theory in terms of alliances should be investigated for continued success and sustainability.
- Full Text:
- Date Issued: 2007
Conservation incentives for private commercial farmers in the thicket biome, Eastern Cape, South Africa
- Authors: Cumming, Tracey Lyn
- Date: 2007
- Subjects: Landowners -- South Africa -- Eastern Cape , Invasive plants -- South Africa -- Eastern Cape , Plant conservation -- South Africa -- Eastern Cape , Conservation of natural resources -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4745 , http://hdl.handle.net/10962/d1006953 , Landowners -- South Africa -- Eastern Cape , Invasive plants -- South Africa -- Eastern Cape , Plant conservation -- South Africa -- Eastern Cape , Conservation of natural resources -- South Africa -- Eastern Cape
- Description: This study sought opportunities to mitigate the pressures of land transformation and alien invader plants on commercial farm land in the thicket biome in the lower reaches of the Fish Kowie Corridor. It had two aims. Firstly, to determine the role incentives could play in mitigating these pressures. Secondly, to determine the characteristics of an incentive programme that would most effectively achieve this. In order to do this, an understanding of landowner activities, needs, opinions and barriers to behaviour; the nature of the pressures on thicket and the nature of the required behaviour to reduce these pressures; and current and past institutional arrangements needed to be achieved. This was done predominantly through a current literature review and personal interviews with landowners and key informants. These findings were used to make recommendations for an effective incentive programme. Landowners showed a preference towards tangible incentives, in particular management assistance, financial compensation and law enforcement. They indicated an aversion to an incentive programme implemented by a government agency, particularly district and provincial government. Rather, landowners showed a propensity towards a nongovernment organisation (NGO) or a farmers group implementing an incentive programme. It was recommended that the two major pressures, namely land transformation and alien invader plants, required different interventions by different agencies in order to be mitigated. The pressure of land transformation required a stewardship model response, with the primary drive being a non-contractual environmental extension service to landowners. The extension service should focus on promoting pro-conservation practises, raising awareness and disseminating information. It should also build a relationship of trust between landowners and the implementing agency. The pressure of alien invader plants would be most effectively addressed through the Working for Water programme. Tangible incentives must be provided to the landowner to induce the costly exercise of alien invader plant control. In particular, the high cost of labour must be addressed. The regulatory incentive of applying laws requiring landowners to control alien invader plants on their land should also be enforced.
- Full Text:
- Date Issued: 2007
- Authors: Cumming, Tracey Lyn
- Date: 2007
- Subjects: Landowners -- South Africa -- Eastern Cape , Invasive plants -- South Africa -- Eastern Cape , Plant conservation -- South Africa -- Eastern Cape , Conservation of natural resources -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4745 , http://hdl.handle.net/10962/d1006953 , Landowners -- South Africa -- Eastern Cape , Invasive plants -- South Africa -- Eastern Cape , Plant conservation -- South Africa -- Eastern Cape , Conservation of natural resources -- South Africa -- Eastern Cape
- Description: This study sought opportunities to mitigate the pressures of land transformation and alien invader plants on commercial farm land in the thicket biome in the lower reaches of the Fish Kowie Corridor. It had two aims. Firstly, to determine the role incentives could play in mitigating these pressures. Secondly, to determine the characteristics of an incentive programme that would most effectively achieve this. In order to do this, an understanding of landowner activities, needs, opinions and barriers to behaviour; the nature of the pressures on thicket and the nature of the required behaviour to reduce these pressures; and current and past institutional arrangements needed to be achieved. This was done predominantly through a current literature review and personal interviews with landowners and key informants. These findings were used to make recommendations for an effective incentive programme. Landowners showed a preference towards tangible incentives, in particular management assistance, financial compensation and law enforcement. They indicated an aversion to an incentive programme implemented by a government agency, particularly district and provincial government. Rather, landowners showed a propensity towards a nongovernment organisation (NGO) or a farmers group implementing an incentive programme. It was recommended that the two major pressures, namely land transformation and alien invader plants, required different interventions by different agencies in order to be mitigated. The pressure of land transformation required a stewardship model response, with the primary drive being a non-contractual environmental extension service to landowners. The extension service should focus on promoting pro-conservation practises, raising awareness and disseminating information. It should also build a relationship of trust between landowners and the implementing agency. The pressure of alien invader plants would be most effectively addressed through the Working for Water programme. Tangible incentives must be provided to the landowner to induce the costly exercise of alien invader plant control. In particular, the high cost of labour must be addressed. The regulatory incentive of applying laws requiring landowners to control alien invader plants on their land should also be enforced.
- Full Text:
- Date Issued: 2007
Consistent testing for lag length in cointegrated relationships
- Authors: Liu, Limin
- Date: 2007
- Subjects: Cointegration -- South Africa , Econometrics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10575 , http://hdl.handle.net/10948/547 , http://hdl.handle.net/10948/d1011715 , Cointegration -- South Africa , Econometrics
- Description: In the past few decades the theory of cointegration has been widely used in the empirical analysis of economic data. The reason is that, it captures the economic notion of a long-run economic relation. One of the problems experienced when applying cointegrated techniques to econometric modelling is the determination of lag lengths for the modelled variables. Applied studies have resulted in contradictory choices for lag length selection. This study reviews and compares some of the well-known information criteria using simulation techniques for bivariate models.
- Full Text:
- Date Issued: 2007
- Authors: Liu, Limin
- Date: 2007
- Subjects: Cointegration -- South Africa , Econometrics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10575 , http://hdl.handle.net/10948/547 , http://hdl.handle.net/10948/d1011715 , Cointegration -- South Africa , Econometrics
- Description: In the past few decades the theory of cointegration has been widely used in the empirical analysis of economic data. The reason is that, it captures the economic notion of a long-run economic relation. One of the problems experienced when applying cointegrated techniques to econometric modelling is the determination of lag lengths for the modelled variables. Applied studies have resulted in contradictory choices for lag length selection. This study reviews and compares some of the well-known information criteria using simulation techniques for bivariate models.
- Full Text:
- Date Issued: 2007
Consolidation of democracy and political culture: an analysis of young elites and the media, the case of Kenya
- Authors: Nzioki, Samuel Mutinda
- Date: 2007
- Subjects: Democracy -- Kenya , Political culture -- Kenya , Kenya -- Politics and government
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: vital:8248 , http://hdl.handle.net/10948/586 , http://hdl.handle.net/10948/d1011680 , Democracy -- Kenya , Political culture -- Kenya , Kenya -- Politics and government
- Description: Democratisation and commitments to transitions to democratic systems has gained momentum as a currency, a necessity, with regard to socio-political and economic development for Africa. In the period following the end of the Cold War in the late 1980’s, there was heightened concern over the pseudo-democratic political establishments in Africa whose negative impact on their economies was blameable for a marked lack of public goods. Political scholars and agencies of Industrialised countries attributed this to stagnation on democratisation process, where consolidation stage of African democracies remains elusive. Kenya is a case and point. This study seeks to contribute to the ensuing debate of crafting versus preconditions to democratic consolidation in Africa. It takes the position that it is the political elite who are the principal agents in designing institution based democracies upon which other socio-economic developments can stand. By focusing on Kenya the study seeks to show that, up to the present moment, the cycle of Kenya’s unconsolidated democracy has been prevailed over by elites’ weakness to commit to deepening democratic values. A sign of hope is therefore in the potential and promise in the emerging young elite in crafting a consolidated democracy in Africa. By focussing on a generational change in leadership, one sees the possibility for Africa to embark on a clearly mapped out and self designed path towards democratic consolidation, led by a younger generation of professional elites. These are not weighed down by postcolonial nationalistic ideals. Their potential and level of commitment to democratic consolidation however needs to be examined. Increased pressures of Westernisation as an after effect of globalisation may have altered/impacted the young elites’ political consciousness and dedication to the African locales. This study thus posits that in order to gauge their inclination to crafting a consolidated democratic landscape of the continent, their political culture must be put under scrutiny. By examining the political culture of the Kenyan young elite this study concluded that more needs to be done to inspire political participation and involvement in this generation. There is general feeling of contentment with the status quo with all its flaws and unchanging poor democratic practises. More has to be done to sever the old undemocratic mentalities and replace them with fresh ideals through wide spread civic education, by using effective instruments like the media and avenues like a reformed school curriculum.
- Full Text:
- Date Issued: 2007
- Authors: Nzioki, Samuel Mutinda
- Date: 2007
- Subjects: Democracy -- Kenya , Political culture -- Kenya , Kenya -- Politics and government
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: vital:8248 , http://hdl.handle.net/10948/586 , http://hdl.handle.net/10948/d1011680 , Democracy -- Kenya , Political culture -- Kenya , Kenya -- Politics and government
- Description: Democratisation and commitments to transitions to democratic systems has gained momentum as a currency, a necessity, with regard to socio-political and economic development for Africa. In the period following the end of the Cold War in the late 1980’s, there was heightened concern over the pseudo-democratic political establishments in Africa whose negative impact on their economies was blameable for a marked lack of public goods. Political scholars and agencies of Industrialised countries attributed this to stagnation on democratisation process, where consolidation stage of African democracies remains elusive. Kenya is a case and point. This study seeks to contribute to the ensuing debate of crafting versus preconditions to democratic consolidation in Africa. It takes the position that it is the political elite who are the principal agents in designing institution based democracies upon which other socio-economic developments can stand. By focusing on Kenya the study seeks to show that, up to the present moment, the cycle of Kenya’s unconsolidated democracy has been prevailed over by elites’ weakness to commit to deepening democratic values. A sign of hope is therefore in the potential and promise in the emerging young elite in crafting a consolidated democracy in Africa. By focussing on a generational change in leadership, one sees the possibility for Africa to embark on a clearly mapped out and self designed path towards democratic consolidation, led by a younger generation of professional elites. These are not weighed down by postcolonial nationalistic ideals. Their potential and level of commitment to democratic consolidation however needs to be examined. Increased pressures of Westernisation as an after effect of globalisation may have altered/impacted the young elites’ political consciousness and dedication to the African locales. This study thus posits that in order to gauge their inclination to crafting a consolidated democratic landscape of the continent, their political culture must be put under scrutiny. By examining the political culture of the Kenyan young elite this study concluded that more needs to be done to inspire political participation and involvement in this generation. There is general feeling of contentment with the status quo with all its flaws and unchanging poor democratic practises. More has to be done to sever the old undemocratic mentalities and replace them with fresh ideals through wide spread civic education, by using effective instruments like the media and avenues like a reformed school curriculum.
- Full Text:
- Date Issued: 2007
Constructing a low-cost, open-source, VoiceXML
- Authors: King, Adam
- Date: 2007 , 2013-07-01
- Subjects: VoiceXML (Document markup language) , Asterisk (Computer file) , Internet telephony , Open source software
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4585 , http://hdl.handle.net/10962/d1004735 , VoiceXML (Document markup language) , Asterisk (Computer file) , Internet telephony , Open source software
- Description: Voice-enabled applications, applications that interact with a user via an audio channel, are used extensively today. Their use is growing as speech related technologies improve, as speech is one of the most natural methods of interaction. They can provide customer support as IVRs, can be used as an assistive technology, or can become an aural interface to the Internet. Given that the telephone is used extensively throughout the globe, the number of potential users of voice-enabled applications is very high. VoiceXML is a popular, open, high-level, standard means of creating voice-enabled applications which was designed to bring the benefits of web based development to services. While VoiceXML is an ideal language for creating these applications, VoiceXML gateways, the hardware and software responsible for interpreting VoiceXML applications and interfacing with the PSTN, are still expensive and so there is a need for a low-cost gateway. Asterisk, and open-source, TDM/VoIP telephony platform, can be used as a low-cost PSTN interface. This thesis investigates adding a VoiceXML service to Asterisk, creating a low-cost VoiceXML prototype gateway which is able to render voice-enabled applications. Following the Component-Based Software Engineering (CBSE) paradigm, the VoiceXML gateway is divided into a set of components which are sourced from the open-source community, and integrated to create the gateway. The browser requires a VoiceXML interpreter (OpenVXI), a Text-To-Speech engine (Festival) and a speech recognition engine (Sphinx 4). The integration of the components results in a low-cost, open-source VoiceXML gateway. System tests show that the integration of the components was successful, and that the system can handle concurrent calls. A fully compliant version of the gateway can be used in the real world to render voice-enabled applications at a low cost. , KMBT_363 , Adobe Acrobat 9.55 Paper Capture Plug-in
- Full Text:
- Date Issued: 2007
- Authors: King, Adam
- Date: 2007 , 2013-07-01
- Subjects: VoiceXML (Document markup language) , Asterisk (Computer file) , Internet telephony , Open source software
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4585 , http://hdl.handle.net/10962/d1004735 , VoiceXML (Document markup language) , Asterisk (Computer file) , Internet telephony , Open source software
- Description: Voice-enabled applications, applications that interact with a user via an audio channel, are used extensively today. Their use is growing as speech related technologies improve, as speech is one of the most natural methods of interaction. They can provide customer support as IVRs, can be used as an assistive technology, or can become an aural interface to the Internet. Given that the telephone is used extensively throughout the globe, the number of potential users of voice-enabled applications is very high. VoiceXML is a popular, open, high-level, standard means of creating voice-enabled applications which was designed to bring the benefits of web based development to services. While VoiceXML is an ideal language for creating these applications, VoiceXML gateways, the hardware and software responsible for interpreting VoiceXML applications and interfacing with the PSTN, are still expensive and so there is a need for a low-cost gateway. Asterisk, and open-source, TDM/VoIP telephony platform, can be used as a low-cost PSTN interface. This thesis investigates adding a VoiceXML service to Asterisk, creating a low-cost VoiceXML prototype gateway which is able to render voice-enabled applications. Following the Component-Based Software Engineering (CBSE) paradigm, the VoiceXML gateway is divided into a set of components which are sourced from the open-source community, and integrated to create the gateway. The browser requires a VoiceXML interpreter (OpenVXI), a Text-To-Speech engine (Festival) and a speech recognition engine (Sphinx 4). The integration of the components results in a low-cost, open-source VoiceXML gateway. System tests show that the integration of the components was successful, and that the system can handle concurrent calls. A fully compliant version of the gateway can be used in the real world to render voice-enabled applications at a low cost. , KMBT_363 , Adobe Acrobat 9.55 Paper Capture Plug-in
- Full Text:
- Date Issued: 2007
Continuous auditing technologies and models
- Authors: Blundell, Adrian Wesley
- Date: 2007
- Subjects: Auditing , Auditing -- Data processing
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9798 , http://hdl.handle.net/10948/476 , http://hdl.handle.net/10948/d1011922 , Auditing , Auditing -- Data processing
- Description: Continuous auditing is not a totally new concept, but it has not been widely implemented, and has existed mostly as a point of debate amongst the auditing fraternity. This may soon change, as continuous auditing has become a topic of great interest, especially in the last decade. This may be due to a combination of reasons. In the last decade, much of the confidence in auditors’ reports was lost due to corporate governance scandals. This also brought about a greater desire for faster, more reliable reporting on which to base decisions. This desire has been transposed into regulations such as the Sarbanes-Oxley act in the United States, which encourages real-time auditing activities, which would benefit from continuous auditing. A second, possible contributing factor to the heightened interest in continuous auditing is that much of the requisite technology has matured to a point where it can be successfully used to implement continuous auditing. It is the technologies which form the focus of this research. It is therefore, the primary objective of this research to investigate and identify the essential technologies, and identify and define their roles within a continuous auditing solution. To explore this area, three models of continuous auditing are compared according to the roles of the technologies within them. The roots of some auditing technologies which can be adapted to the paradigm of continuous auditing are explored, as well as new technologies, such as XML-based reporting languages. In order to fully explore these technologies, the concepts of data integrity and data quality are first defined and discussed, and some security measures which contribute to integrity are identified. An obstacle to implementing a continuous model is that even with the newly available technologies, the multitudes of systems which are used in organisations, produce data in a plethora of data formats. In performing an audit the continuous auditing system needs to first gather this data and then needs to be able to compare “apples with apples”. Therefore, the technologies which can be used to acquire and standardise the data are identified.
- Full Text:
- Date Issued: 2007
- Authors: Blundell, Adrian Wesley
- Date: 2007
- Subjects: Auditing , Auditing -- Data processing
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9798 , http://hdl.handle.net/10948/476 , http://hdl.handle.net/10948/d1011922 , Auditing , Auditing -- Data processing
- Description: Continuous auditing is not a totally new concept, but it has not been widely implemented, and has existed mostly as a point of debate amongst the auditing fraternity. This may soon change, as continuous auditing has become a topic of great interest, especially in the last decade. This may be due to a combination of reasons. In the last decade, much of the confidence in auditors’ reports was lost due to corporate governance scandals. This also brought about a greater desire for faster, more reliable reporting on which to base decisions. This desire has been transposed into regulations such as the Sarbanes-Oxley act in the United States, which encourages real-time auditing activities, which would benefit from continuous auditing. A second, possible contributing factor to the heightened interest in continuous auditing is that much of the requisite technology has matured to a point where it can be successfully used to implement continuous auditing. It is the technologies which form the focus of this research. It is therefore, the primary objective of this research to investigate and identify the essential technologies, and identify and define their roles within a continuous auditing solution. To explore this area, three models of continuous auditing are compared according to the roles of the technologies within them. The roots of some auditing technologies which can be adapted to the paradigm of continuous auditing are explored, as well as new technologies, such as XML-based reporting languages. In order to fully explore these technologies, the concepts of data integrity and data quality are first defined and discussed, and some security measures which contribute to integrity are identified. An obstacle to implementing a continuous model is that even with the newly available technologies, the multitudes of systems which are used in organisations, produce data in a plethora of data formats. In performing an audit the continuous auditing system needs to first gather this data and then needs to be able to compare “apples with apples”. Therefore, the technologies which can be used to acquire and standardise the data are identified.
- Full Text:
- Date Issued: 2007
Contributions to the use of microalgae in estuarine freshwater reserve determinations
- Authors: Snow, Gavin Charles
- Date: 2007
- Subjects: Microalgae -- South Africa , Estuarine ecology -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10620 , http://hdl.handle.net/10948/709 , Microalgae -- South Africa , Estuarine ecology -- South Africa
- Description: The ecologist Garrett Hardin (1968) introduced a useful concept called the tragedy of the commons, which describes how ecological resources become threatened or lost. The term “commons” is based on the commons of old English villages and is symbolic of a resource that is shared by a group of people. If every person were to use each resource in a sustainable fashion it would be available in perpetuity. However, if people use more than their share they would only increase their personal wealth to the detriment of others. In addition, an increase in the population would mean that the size of each share would have to decrease to accommodate the larger number of people. As a result, resources are threatened by personal greed and uncontrolled population growth. Freshwater is an example of a common resource that is under threat in South Africa where the average annual rainfall is less than 60 percent of the global average (Mukheibir & Sparks 2006). The increasing demands for freshwater as well as its eutrophication are major concerns with regards to estuarine health, environmental resource management and human health. The correct management of water is necessary to ensure that it is utilised in a sustainable manner. The National Water Act (No. 36 of 1998) has provided the rights to water for basic human needs and for sustainable ecological function; the Basic Human Needs Reserve and Ecological Reserve are both provided as a right in law. The amount of water necessary for an estuary to retain an acceptable ecological status, known as the Estuarine Ecological Reserve, is determined through the implementation of procedures (rapid, intermediate or comprehensive) compiled by the Department of Water Affairs and Forestry (1999) in its Resource Directed Measures (RDM) for the Protection of Water Resources. The impact of restricted flow on estuaries can be reduced by manipulating the water released from impoundments, the regulation of water abstractions within the river catchment or both (Hirji et al. 2002). The reserve assessment method is designed to evaluate ecosystem requirements by employing groups of specialists from different disciplines. In South Africa, this includes hydrologists, sedimentologists, water chemists and biologists (including microalgae specialists). The use of microalgae in ecological assessments has largely been based on research that was initiated at the Nelson Mandela Metropolitan University (formerly University of Port Elizabeth) and subsequently at Rhodes University (Grahamstown) and the University of KwaZulu Natal (Durban). The microalgal research can be divided into two main focus areas; phytoplankton and benthic microalgae
- Full Text:
- Date Issued: 2007
- Authors: Snow, Gavin Charles
- Date: 2007
- Subjects: Microalgae -- South Africa , Estuarine ecology -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10620 , http://hdl.handle.net/10948/709 , Microalgae -- South Africa , Estuarine ecology -- South Africa
- Description: The ecologist Garrett Hardin (1968) introduced a useful concept called the tragedy of the commons, which describes how ecological resources become threatened or lost. The term “commons” is based on the commons of old English villages and is symbolic of a resource that is shared by a group of people. If every person were to use each resource in a sustainable fashion it would be available in perpetuity. However, if people use more than their share they would only increase their personal wealth to the detriment of others. In addition, an increase in the population would mean that the size of each share would have to decrease to accommodate the larger number of people. As a result, resources are threatened by personal greed and uncontrolled population growth. Freshwater is an example of a common resource that is under threat in South Africa where the average annual rainfall is less than 60 percent of the global average (Mukheibir & Sparks 2006). The increasing demands for freshwater as well as its eutrophication are major concerns with regards to estuarine health, environmental resource management and human health. The correct management of water is necessary to ensure that it is utilised in a sustainable manner. The National Water Act (No. 36 of 1998) has provided the rights to water for basic human needs and for sustainable ecological function; the Basic Human Needs Reserve and Ecological Reserve are both provided as a right in law. The amount of water necessary for an estuary to retain an acceptable ecological status, known as the Estuarine Ecological Reserve, is determined through the implementation of procedures (rapid, intermediate or comprehensive) compiled by the Department of Water Affairs and Forestry (1999) in its Resource Directed Measures (RDM) for the Protection of Water Resources. The impact of restricted flow on estuaries can be reduced by manipulating the water released from impoundments, the regulation of water abstractions within the river catchment or both (Hirji et al. 2002). The reserve assessment method is designed to evaluate ecosystem requirements by employing groups of specialists from different disciplines. In South Africa, this includes hydrologists, sedimentologists, water chemists and biologists (including microalgae specialists). The use of microalgae in ecological assessments has largely been based on research that was initiated at the Nelson Mandela Metropolitan University (formerly University of Port Elizabeth) and subsequently at Rhodes University (Grahamstown) and the University of KwaZulu Natal (Durban). The microalgal research can be divided into two main focus areas; phytoplankton and benthic microalgae
- Full Text:
- Date Issued: 2007
Cost-benefit analysis of land restoration in the Assegaaibos Catchment Area with regard to water yield and tourism benefit
- Authors: Currie, Bianca
- Date: 2007
- Subjects: Reclamation of land -- Economic aspects -- South Africa -- Assegaaibos Catchment Area , Land use -- Environmental aspects -- South Africa -- Assegaaibos Catchment Area
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10751 , http://hdl.handle.net/10948/726 , Reclamation of land -- Economic aspects -- South Africa -- Assegaaibos Catchment Area , Land use -- Environmental aspects -- South Africa -- Assegaaibos Catchment Area
- Description: With the emergence of the new field of resource economics, one now has the ability to value and to include natural resources in decision making. This thesis aims to explore the valuation of natural resources by reviewing the economic values, techniques, methods and ecological aspects of restoration. Assegaaibos mountain catchment in the Western Cape Province has been used as a case-study example. A cost-benefit analysis of the restoration of the mountain catchment, in terms of the direct benefits of water and tourism, has been performed. The costs of restoration were observed to see whether they outweighed the benefits (income) derived (water and tourism). The results show that the water and tourism benefits did outweigh the costs of a basic restoration scenario. However, the basic restoration scenario did not fulfil the ecological requirements of the project. The results also illustrated that in the moderate restoration scenario, costs only outweighed the benefits when a three percent discount rate was applied. With the optimistic restoration scenario, costs outweighed benefits only when an eight percent discount rate was used. In the comprehensive restoration scenario, costs were shown to outweigh by far the water and tourism benefits over a thirty-year time frame. However, it should be noted that the deterioration of the environment (accelerated erosion, reinvasion, reduced water quality) was not factored into the costs of failure to rehabilitate.
- Full Text:
- Date Issued: 2007
- Authors: Currie, Bianca
- Date: 2007
- Subjects: Reclamation of land -- Economic aspects -- South Africa -- Assegaaibos Catchment Area , Land use -- Environmental aspects -- South Africa -- Assegaaibos Catchment Area
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10751 , http://hdl.handle.net/10948/726 , Reclamation of land -- Economic aspects -- South Africa -- Assegaaibos Catchment Area , Land use -- Environmental aspects -- South Africa -- Assegaaibos Catchment Area
- Description: With the emergence of the new field of resource economics, one now has the ability to value and to include natural resources in decision making. This thesis aims to explore the valuation of natural resources by reviewing the economic values, techniques, methods and ecological aspects of restoration. Assegaaibos mountain catchment in the Western Cape Province has been used as a case-study example. A cost-benefit analysis of the restoration of the mountain catchment, in terms of the direct benefits of water and tourism, has been performed. The costs of restoration were observed to see whether they outweighed the benefits (income) derived (water and tourism). The results show that the water and tourism benefits did outweigh the costs of a basic restoration scenario. However, the basic restoration scenario did not fulfil the ecological requirements of the project. The results also illustrated that in the moderate restoration scenario, costs only outweighed the benefits when a three percent discount rate was applied. With the optimistic restoration scenario, costs outweighed benefits only when an eight percent discount rate was used. In the comprehensive restoration scenario, costs were shown to outweigh by far the water and tourism benefits over a thirty-year time frame. However, it should be noted that the deterioration of the environment (accelerated erosion, reinvasion, reduced water quality) was not factored into the costs of failure to rehabilitate.
- Full Text:
- Date Issued: 2007
Creating value through customer relationships in the services sector
- Authors: Allie, Hisham
- Date: 2007
- Subjects: Customer services , Value added
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8740 , http://hdl.handle.net/10948/790 , Customer services , Value added
- Description: Many academic studies in the past have focussed on how to create value for businesses in terms of adding profit to the bottom line through performance, and many argue that adding value for the client is also viewed as a profitable business strategy. This strategy translates as a win-win business relationship since long-term relationships ensure customer loyalty, customer retention and repeat business. In the services sector, it is difficult to quantify the worth or value that a particular service has since services are intangible products. The perception of value of such a service is known as “perceived value” since value recognition rests with the consumer who attempts to quantify the worth of that service. It is generally accepted in the services sector that establishing long-term, mutually beneficial, meaningful business relationships add value for the client and helps them to attach a value to the services that company provides. A company cannot establish such relationships without the help of its employees who represents the face of the organisation and implements the value adding strategy on the organisation’s behalf. Recent studies have begun to address this, examining value creation in business relationships in the context of the sale of tangible goods. The process of value creation for customers in services relationships remains underresearched. Perceived value explains why customers choose one particular service over another, why service companies gain competitive advantage by maintaining genuine longterm customer relationships, and why “the personal touch”, created through emotional attributes such as trust, caring and empathy, adds value from customers’ perspective. This dissertation presents a study of perceived value from the perspective of the customer within the context of the delivery of a credence product in a services relationship model. Using grounded theory methodology; following in-depth interviews with consumers of general insurance, a number of customer-value creation dimensions for businesses have been identified. Parallel interviews with members of staff from the supplier company add a further perspective. This research demonstrates how organisations or suppliers in the services industry can add value when delivering a credence product in a services relationship context. It is believed that an understanding of the value-adding dimensions can be implemented to create opportunities to build value for customers, with commensurate benefits for suppliers. Following analysis of the interviews held with each buyer, a total of six value dimensions are identified in the findings chapter. Each dimension is individually described, discussed, and illustrated with quotations from customers and supplier’s staff. Other issues relating to value arising from the interviews are examined in the discussion chapter. Three areas for further research are proposed in the conclusion.
- Full Text:
- Date Issued: 2007
- Authors: Allie, Hisham
- Date: 2007
- Subjects: Customer services , Value added
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8740 , http://hdl.handle.net/10948/790 , Customer services , Value added
- Description: Many academic studies in the past have focussed on how to create value for businesses in terms of adding profit to the bottom line through performance, and many argue that adding value for the client is also viewed as a profitable business strategy. This strategy translates as a win-win business relationship since long-term relationships ensure customer loyalty, customer retention and repeat business. In the services sector, it is difficult to quantify the worth or value that a particular service has since services are intangible products. The perception of value of such a service is known as “perceived value” since value recognition rests with the consumer who attempts to quantify the worth of that service. It is generally accepted in the services sector that establishing long-term, mutually beneficial, meaningful business relationships add value for the client and helps them to attach a value to the services that company provides. A company cannot establish such relationships without the help of its employees who represents the face of the organisation and implements the value adding strategy on the organisation’s behalf. Recent studies have begun to address this, examining value creation in business relationships in the context of the sale of tangible goods. The process of value creation for customers in services relationships remains underresearched. Perceived value explains why customers choose one particular service over another, why service companies gain competitive advantage by maintaining genuine longterm customer relationships, and why “the personal touch”, created through emotional attributes such as trust, caring and empathy, adds value from customers’ perspective. This dissertation presents a study of perceived value from the perspective of the customer within the context of the delivery of a credence product in a services relationship model. Using grounded theory methodology; following in-depth interviews with consumers of general insurance, a number of customer-value creation dimensions for businesses have been identified. Parallel interviews with members of staff from the supplier company add a further perspective. This research demonstrates how organisations or suppliers in the services industry can add value when delivering a credence product in a services relationship context. It is believed that an understanding of the value-adding dimensions can be implemented to create opportunities to build value for customers, with commensurate benefits for suppliers. Following analysis of the interviews held with each buyer, a total of six value dimensions are identified in the findings chapter. Each dimension is individually described, discussed, and illustrated with quotations from customers and supplier’s staff. Other issues relating to value arising from the interviews are examined in the discussion chapter. Three areas for further research are proposed in the conclusion.
- Full Text:
- Date Issued: 2007
Creative misreadings: allegory in Tracey Rose's Ciao Bella
- Authors: Bateman, Genevieve
- Date: 2007
- Subjects: Rose, Tracey, 1974- Artists -- South Africa Women artists -- South Africa Performance artists -- South Africa Women in art
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: vital:2473 , http://hdl.handle.net/10962/d1009506
- Description: This thesis will aim to investigate the extent to which Tracey Rose's Ciao Bella can be said to allegorically perform a dialectical enfolding of the dichotomous categories of meaning/nonmeaning; image/text; past/present and original/translation. The dual concepts of performance and performativity will be utilized as a means to explore the notion of interpretation as a meaning-making process and as an engagement between artist, artwork and viewer that is necessarily open-ended and in a state of constant change and flux. Rose's performance of Ciao Bella will be read as one that questions the illusion of unmediated representation by parodying and creatively misreading a multiplicity of visual, textual and musical representations so as to foreground the politics of representation. The representational figure of allegory, as one that defines itself in opposition to the Romantic conception of the unified symbol, will be put to work so as to reveal the ways in which Rose's performance works to critically undermine various positivistic attitudes toward self-identity, gender, race, politics, history, authorial intention and interpretation.
- Full Text:
- Date Issued: 2007
- Authors: Bateman, Genevieve
- Date: 2007
- Subjects: Rose, Tracey, 1974- Artists -- South Africa Women artists -- South Africa Performance artists -- South Africa Women in art
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: vital:2473 , http://hdl.handle.net/10962/d1009506
- Description: This thesis will aim to investigate the extent to which Tracey Rose's Ciao Bella can be said to allegorically perform a dialectical enfolding of the dichotomous categories of meaning/nonmeaning; image/text; past/present and original/translation. The dual concepts of performance and performativity will be utilized as a means to explore the notion of interpretation as a meaning-making process and as an engagement between artist, artwork and viewer that is necessarily open-ended and in a state of constant change and flux. Rose's performance of Ciao Bella will be read as one that questions the illusion of unmediated representation by parodying and creatively misreading a multiplicity of visual, textual and musical representations so as to foreground the politics of representation. The representational figure of allegory, as one that defines itself in opposition to the Romantic conception of the unified symbol, will be put to work so as to reveal the ways in which Rose's performance works to critically undermine various positivistic attitudes toward self-identity, gender, race, politics, history, authorial intention and interpretation.
- Full Text:
- Date Issued: 2007
Cultural values and leadership styles of middle level managers in a private sector hospitals in the Eastern Cape
- Authors: Boguslavsky, Marianna
- Date: 2007
- Subjects: Hospitals, Proprietary -- South Africa -- Eastern Cape , Leadership -- South Africa -- Eastern Cape , Middle managers -- South Africa -- Eastern Cape , Corporate culture -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10080 , http://hdl.handle.net/10948/478 , http://hdl.handle.net/10948/d1011927 , Hospitals, Proprietary -- South Africa -- Eastern Cape , Leadership -- South Africa -- Eastern Cape , Middle managers -- South Africa -- Eastern Cape , Corporate culture -- South Africa -- Eastern Cape
- Description: In recent years, South Africa has seen increasing cultural diversification with regard to the appointment of managers in private healthcare facilities. However, research conducted in this area remains extremely limited. The aim of the present study was to explore and describe cultural values and leadership styles of middle managers at a private sector hospital in the Eastern Cape. Hofstede’s (1980, a ) model of cultural values served as a theoretical framework to conceptualise this study. The study was qualitative in nature and made use of in-depth research interviews conducted with a diverse sample of middle managers. The researcher made use of homogeneous and convenience sampling and utilised five participants. The qualitative data was analysed using Tesch’s (1990, in De Vos, 2002) method of analysis. Results revealed that despite the differences in personal culture, most of the managers are similar in their leadership styles and are also affected by the organizational culture. The results of the study contribute to a better understanding of the influence of cultural values and leadership styles in South Africa and will thereby benefit health institutions in their dealings with their modern day multi-cultural management staff.
- Full Text:
- Date Issued: 2007
- Authors: Boguslavsky, Marianna
- Date: 2007
- Subjects: Hospitals, Proprietary -- South Africa -- Eastern Cape , Leadership -- South Africa -- Eastern Cape , Middle managers -- South Africa -- Eastern Cape , Corporate culture -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10080 , http://hdl.handle.net/10948/478 , http://hdl.handle.net/10948/d1011927 , Hospitals, Proprietary -- South Africa -- Eastern Cape , Leadership -- South Africa -- Eastern Cape , Middle managers -- South Africa -- Eastern Cape , Corporate culture -- South Africa -- Eastern Cape
- Description: In recent years, South Africa has seen increasing cultural diversification with regard to the appointment of managers in private healthcare facilities. However, research conducted in this area remains extremely limited. The aim of the present study was to explore and describe cultural values and leadership styles of middle managers at a private sector hospital in the Eastern Cape. Hofstede’s (1980, a ) model of cultural values served as a theoretical framework to conceptualise this study. The study was qualitative in nature and made use of in-depth research interviews conducted with a diverse sample of middle managers. The researcher made use of homogeneous and convenience sampling and utilised five participants. The qualitative data was analysed using Tesch’s (1990, in De Vos, 2002) method of analysis. Results revealed that despite the differences in personal culture, most of the managers are similar in their leadership styles and are also affected by the organizational culture. The results of the study contribute to a better understanding of the influence of cultural values and leadership styles in South Africa and will thereby benefit health institutions in their dealings with their modern day multi-cultural management staff.
- Full Text:
- Date Issued: 2007
Cytokine properties of CD23 on human Eosinophilic cells
- Authors: Ferreira, Lauren
- Date: 2007
- Subjects: Cytokines , CD23 antigen , Eosinophil
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10333 , http://hdl.handle.net/10948/503 , http://hdl.handle.net/10948/d1012001 , Cytokines , CD23 antigen , Eosinophil
- Description: CD23, the low affinity IgE receptor, is expressed by various cell types and has numerous functions depending on the form of the protein, its interaction with various ligands and the type of cell involved. CD23 is pivotal in the regulation of IgE, with the soluble form involved in up-regulation, while the membrane bound form is involved in the down-regulation. It is clear why it is believed to be a central molecule in allergic responses, and a therapeutic target for the treatment of allergic disease. In this study a recombinant form of the entire extracellular domain of the protein, exCD23, was produced by PCR cloning and expressed in E. coli. His•Tag™s were introduced onto the C-terminus and N-terminus, respectively, in order to simplify the purification procedure. After renaturation and purification, the recombinant exCD23 bound IgE, indicating its activity. From the IgE binding studies it was established that the position of the tag did not influence the binding. GST•Tagged™ exCD23 was also produced in an attempt to increase the solubility of the recombinant protein, but this proved unsuccessful. Butyrate differentiated EoL-1 cells were treated with the Nterminal His•Tagged™ exCD23, and the protein appeared to suppress the secretion of the constitutively expressed cytokines, especially IL-8 and IFN- , when compared to untreated cells. In addition, treatment of the EoL-1 cells with exCD23 had a significant proliferative effect, but could not induce differentiation of this cell line into mature eosinophilic-like cells.
- Full Text:
- Date Issued: 2007
- Authors: Ferreira, Lauren
- Date: 2007
- Subjects: Cytokines , CD23 antigen , Eosinophil
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10333 , http://hdl.handle.net/10948/503 , http://hdl.handle.net/10948/d1012001 , Cytokines , CD23 antigen , Eosinophil
- Description: CD23, the low affinity IgE receptor, is expressed by various cell types and has numerous functions depending on the form of the protein, its interaction with various ligands and the type of cell involved. CD23 is pivotal in the regulation of IgE, with the soluble form involved in up-regulation, while the membrane bound form is involved in the down-regulation. It is clear why it is believed to be a central molecule in allergic responses, and a therapeutic target for the treatment of allergic disease. In this study a recombinant form of the entire extracellular domain of the protein, exCD23, was produced by PCR cloning and expressed in E. coli. His•Tag™s were introduced onto the C-terminus and N-terminus, respectively, in order to simplify the purification procedure. After renaturation and purification, the recombinant exCD23 bound IgE, indicating its activity. From the IgE binding studies it was established that the position of the tag did not influence the binding. GST•Tagged™ exCD23 was also produced in an attempt to increase the solubility of the recombinant protein, but this proved unsuccessful. Butyrate differentiated EoL-1 cells were treated with the Nterminal His•Tagged™ exCD23, and the protein appeared to suppress the secretion of the constitutively expressed cytokines, especially IL-8 and IFN- , when compared to untreated cells. In addition, treatment of the EoL-1 cells with exCD23 had a significant proliferative effect, but could not induce differentiation of this cell line into mature eosinophilic-like cells.
- Full Text:
- Date Issued: 2007
Depressive disorders and chronic comorbid disease states: a pharmacoepidemiological evaluation
- Authors: Kritiotis, Lia Costas
- Date: 2007
- Subjects: Depression, Mental , Child psychopathology , Adolescent psychopathology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10151 , http://hdl.handle.net/10948/653 , Depression, Mental , Child psychopathology , Adolescent psychopathology
- Description: The treatment of Depressive Disorders in patients with chronic comorbid disease states warrants careful consideration of the risk-benefit ratio pertaining to the pharmacokinetic and pharmacodynamic characteristics of the antidepressant being considered, against the physiological susceptibilities of the patient; potential drug-drug interactions and depressive symptoms. The primary aim of this study was to investigate the relationship between Depressive Disorders and the most frequently diagnosed chronic comorbid disease states in a depressed South African study population; and to comment on the appropriateness of antidepressants prescribed to these patients. This retrospective drug utilisation study consisted of two parts: the first part focused on the prevalence of the most frequently diagnosed chronic comorbidities in a depressed South African population (N = 21 171). The three most prevalent chronic comorbid disease states were Hypertension (52.87 percent), Lipid Disorders (20.40 percent) and Arthritis (16.70 percent). The second part of the study included an assessment of the antidepressants prescribed to depressed patients in 2004 (N = 6 150). Emphasis was placed on the suitability of antidepressants selected for depressed adult patients (18 years of age and older) with comorbid Hypertension, Lipid Disorders or Arthritis. SSRIs were prescribed most frequently to the depressed patients during 2004 (59.67 percent). SSRIs are the suggested first-line treatments for depressed patients with multiple chronic comorbid disease states. However, of the SSRIs, fluoxetine has the least favourable pharmacokinetic profile and was found to be the antidepressant prescribed most often. Amitriptyline, which was the TCA prescribed most frequently, produces the greatest degree of anticholinergic, sedative and hypotensive effects, relative to other agents in the same antidepressant class. Thus, it is not recommended as a first-line antidepressant, especially in depressed patients with comorbidities. This study identifies potential areas of intervention regarding antidepressant prescribing in depressed individuals with chronic comorbid disease states and offers recommendations to promote the selection of optimal, individualised drug treatment strategies for these patients.
- Full Text:
- Date Issued: 2007
- Authors: Kritiotis, Lia Costas
- Date: 2007
- Subjects: Depression, Mental , Child psychopathology , Adolescent psychopathology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10151 , http://hdl.handle.net/10948/653 , Depression, Mental , Child psychopathology , Adolescent psychopathology
- Description: The treatment of Depressive Disorders in patients with chronic comorbid disease states warrants careful consideration of the risk-benefit ratio pertaining to the pharmacokinetic and pharmacodynamic characteristics of the antidepressant being considered, against the physiological susceptibilities of the patient; potential drug-drug interactions and depressive symptoms. The primary aim of this study was to investigate the relationship between Depressive Disorders and the most frequently diagnosed chronic comorbid disease states in a depressed South African study population; and to comment on the appropriateness of antidepressants prescribed to these patients. This retrospective drug utilisation study consisted of two parts: the first part focused on the prevalence of the most frequently diagnosed chronic comorbidities in a depressed South African population (N = 21 171). The three most prevalent chronic comorbid disease states were Hypertension (52.87 percent), Lipid Disorders (20.40 percent) and Arthritis (16.70 percent). The second part of the study included an assessment of the antidepressants prescribed to depressed patients in 2004 (N = 6 150). Emphasis was placed on the suitability of antidepressants selected for depressed adult patients (18 years of age and older) with comorbid Hypertension, Lipid Disorders or Arthritis. SSRIs were prescribed most frequently to the depressed patients during 2004 (59.67 percent). SSRIs are the suggested first-line treatments for depressed patients with multiple chronic comorbid disease states. However, of the SSRIs, fluoxetine has the least favourable pharmacokinetic profile and was found to be the antidepressant prescribed most often. Amitriptyline, which was the TCA prescribed most frequently, produces the greatest degree of anticholinergic, sedative and hypotensive effects, relative to other agents in the same antidepressant class. Thus, it is not recommended as a first-line antidepressant, especially in depressed patients with comorbidities. This study identifies potential areas of intervention regarding antidepressant prescribing in depressed individuals with chronic comorbid disease states and offers recommendations to promote the selection of optimal, individualised drug treatment strategies for these patients.
- Full Text:
- Date Issued: 2007